The present invention relates to a wire drive apparatus for a wire saw, that is used for circulating the cutting wire endlessly at a running speed and with a tension as required when the structures etc. made of reinforced concrete are cut with a wire-saw.
As a wire drive apparatus, the inventor recently developed a device which consists of a carriage, a wire drive pulley for endless circulation of the cutting wire and a pulley drive means for turning the wire drive pulley that are installed on the carriage, rails laid on the surface of the road or floor, the front and rear wheels that hold the carriage so as to allow it traveling on the rails and the wheel drive means for turning the front and rear wheels. The wire drive apparatus, while it endlessly rotates the cutting wire that is wound round the object of cutting by way of the wire drive pulley at a required speed, moves the carriage along the rails by way of the front and rear wheels away from the object of cutting and always keeps a required tension in the cutting wire, thus the object of cutting is gradually cut out.
Since the conventional wire drive apparatus, though it possesses front and rear wheels rolling on the rails as described above, lacks the means to move around on the surface of road, floor and so forth (It is called the base surface generally in this specification.), where rails are not laid, when the wire drive apparatus that weighs 1-1.5 ton or sometimes heavier than that is moved on the base surface in the field of work, for instance, in case the apparatus that lies on the base surface is placed on the rails or vice versa, a crane is indispensable. In such a case that large blocks of stone are cut out in a stone pit, there is generally a large space in the stone pit and cranes are invariably provided with for transportation of blocks of stone that have been cut out. Therefore, for the above-mentioned transfer of the wire drive apparatus on the base surface these cranes are readily available.
However, in such a case that the structures of reinforced concrete of the buildings, bridges, foundations, walls of subway tunnels etc. are cut out by the wire saw and partly dismantled, cranes are not always freely used, because the working space is generally small and complicated and sometimes the wire drive apparatus is placed on the floor indoors. Furthermore, unlike the case of the simple cutting out of large blocks of stone at the stone pit, the cutting operation of the reinforced concrete structures in most cases consists of a combination of plural partial cuttings whose locations and directions are different and the place of installation of the wire drive apparatus should be changed very often. Therefore, even if cranes can be freely used, transfer of the wire drive apparatus by the crane every time would lead to a drop in the work efficiency.
The present invention has for its object to offer a wire drive apparatus for the wire saw that is easily movable on the base surface.